For a process of this type, it is conceivable to use a drawing means, such as for a brush or a pen, to apply the coating direct to the part-surface of the lamp. However, this is complex and requires a relatively long time. Furthermore, there are problems with applying the coating with required degree of accuracy, for example if inaccurate production or assembly processes result in deviations from the normal shape of the part-surface, in particular if a bulb of the lamp is not oriented perpendicularly.